Silk screen printing machine



May 29, 1951 G. w. REINKE sILx scREEN PRINTING MACHINE 13 Sheets-Sheet 1Filed Nov. 22, 1946 |||||||||I l||||l I1 11.. .A -.-Il

| l l l May 29, 1951 G, w, RElNKE 2,555,096

SILK SCREEN PRINTINGMACHINE Filed Nov. 22, 194e 1s sheets-sheet 2 @wwwMs.

May 29, 1951 G. w. REINK SILK SCREEN PRINTING MACHINE Filed NOV. 22,1946 15 Sheets-Sheet 5 INVENTOR.

13 y@ WM E @Mayi G. w. REINKE SILK SCREEN PRINTING MACHINE May 29, 195115 Sheets-Sheet 4 Filed NOV. 22, 1946 May 29, 1951 G. w. REINKE SILKscREEN PRINTING MACHINE 13 Sheets-Sheet 5 Filed Nov. 22, 1946 INVENTOR.660739@ WcL'IZ@ May 29, 1951 G. w. 'REINKE 2,555,096

SILK scREEN PRINTING MACHINE Filed Nov. 22, 1946 15 Sheets-Sheet 6 1NTOR. 6607396' WRE/Z/rc May 29, 1951 G. w. REINKE y SILK scREEN PRINTINGMACHINE 13 Sheets-Sheet 7 INVENTOR. f GcmkgcVl/Reme IIIIIIII Filed Nov.22, 1946 IIIIIIIIIIIIIII rial- I I I I I I IIIIII I I I l I I I I l I II Ma 29, 1951 G. w. REINKE 2,555,096

SILK SCREEN PRINTING MACHINE Filed Nov. 22, 194e 155 sheets-sheet s mi|||||||.l

May 29, 1951 G. REINKE SILK SCREEN PRINTING MACHINE 13 Sheets-Sheet 9Filed Nov. 22, 1946 May 29, 1951 G. w. REINKE SILK SCREEN PRINTINGMACHINE 15 sheets-shee't 1o Filed Nov. 22, 1946 LILI.

INVENToR. GCOTgcJ/IRCZ'lZ/c May 29, 1951 G. w. REINKE 2,555,096

SILK SCREEN PRINTING MACHINE Filed Nov. 22, 1946 l 13 Sheets-Sheet 1l "f29, 1951 G. w. REINKE 2,555,096

SILK SCREEN PRINTING MACHINE Filed NOV. 22, 1946 13 Sheets-Sheet l2 May29, 1951 Filed Nov. 22, 1946 9 IF might 7@ z G. W. REINKE SILK SCREENPRINTING MACHINE 115 Sheets-Sheet 13 1N VEN TOR.

Patented May 29, 1951 SILK SCREEN PRINTING MACHINE George W. Reinke,Park Ridge, Ill., assignor to Roto-Screen Company, Chicago, Ill., acorporation of Illinois Application November 22, 1946, Serial No.711,510

(Cl. lOl-424) 11 Claims. l

This invention relates in general to printing machines and particularlyto a silk screen printing machine having novel features to produce a nequality of reproduction.

There have been a number of attempts in the past to produce asatisfactory silk screen printing machine, but numerous difficultieshave arisen. For example, properly registering the paper for feeding tothe screen has presented a serious problem with the result that earliermachines have been unable to perform as fine a quality of work' as thatwhich could be 0btained by the hand printing process. Therefore, whenfine quality work was necessary, such as that comparable to alithographie process, the hand printing was resorted to.

These earlier machines presented other difficulties such as the propercoordination of the various parts, and the screen itself was so locatedthat it could not be easily reached for cleaning both sides thereof.

All of the various disadvantages presented by earlier screen printingmachines have been overcome in the invention disclosed herein, andnumerous other advantages have resulted therefrom. It is, therefore, oneof the principal objects of the present invention to provide a silkscreen printing machine which will produce a fine quality of workcomparable to that of a lithographic process in full four color processreproduction and which will reproduce up to approximately 133 lineshalf-tone.

Another object is to provide a machine of the character herein describedwith novel sheet feeding registering means whereby full four colorreproduction may be obtained comparable to that of a lithographicprocess.

A further object is to provide a novel drive mechanism for a silk screenprinting machine for properly coordinating the various steps in theprinting process and which will permit proper and accurate registeringof the paper.

. Still another object is to provide a novel inking fountain arrangementwhereby proper ink distribution is obtained in properly timed relationwith movement of the screen.

A still further object is to provide novel operating and adjustingmechanism for the squeegee bar whereby multi-color printing may takeplace and the amount of ink forced through the screen thereby may becontrolled.

Another and more specific object of the invention is to provide a novelmounting and actuating means for the screen to facilitate cleaning bothsides thereof. The manner of' mounting and the adjustability of thescreen also being such that the screen fra-me may be moved for properregistration instead of the register pins, thus permitting paper to befed to the same point at all times.

Other objects and advantages of the invention will become apparent uponreading the following description taken in connection with theaccompanying drawings in which:

Fig. 1 is a side elevational view of the machine;

Fig. 2 is a rear end elevational View;

Fig. 3 is an enlarged sectional View taken substantially along the planeof line 3--3 of Figs. 1 and 4;

Fig. 4 is an enlarged vertical longitudinal sectional View through apart of the machine taken substantially along the plane of line 4 4 ofFig. 3 and showing the screen in its uppermost position;

Fig. 5 is a sectional view similar to Fig. 4, but showing the screen inits lowermost position;

Fig. 6 is a view similar to Figs. 4 and 5 but showing the parts in astill different position;

Fig. 7 is a side elevational view partly in section of the inkingfountain and the ink feed bar;

Fig. 8 is a fragmentary front elevational view of that part of thedevice shown in Fig. 7;

Fig. 9 is a transverse sectional view taken substantialy along the planeof line 9 9 of Fig. 5;

Fig. 10 is a front end elevational view partly in section and takensubstantially along the plane of line D-i of Fig. 11;

Fig. l1 is an enlarged fragmentary side elevational view with certainparts removed to show details and taken substantially along the plane ofline Il-ll of Fig. 3;

Fig. l2 is a fragmentary longitudinal sectional View taken substantiallyalong the plane of line 42-12 of Fig. 10;

Fig. 13 is a detailed end elevational View of the drive mechanism takensubstantially along the plane of line 'I3- i3 of Fig. l;

Fig. 14 is a plan view of the drive mechanism shown in Fig. 13;

Fig. 15 is a vertical sectional view of the drive mechanism takensubstantially along the plane of line l5--l5 0f Fig. 13;

Fig. 16 is a fragmentary plan View of the printing drum and sheetgripper assembly;

Fig. 17 is a plan View of the screen and screen frame with parts brokenaway to show details;

Fig. 18 is fragmentary transverse sectional view taken substantiallyalong the plane of line iS-IS of Fig. 17 and including in addition therack guide;

Fig. 19 is a fragmentary side elevational view of the scilneen frameshown in Fig. 17;

Fig. 20 is a fragmentary sectional view of the screen frame takensubstantially along the plane of line Ml-2Q of Fig. 17; and

Fig. 21 is a fragmentary sectional View taken substantially along theplane of line 2i-2I of Fig. 20.

The silk screen printing machine disclosed herein comprises in general amain frame on which the various operating mechanism is adapted to bemounted. The silk screen through which the printing is done is locatedangularly for ease in cleaning and is mounted for reciprocation insuitable guides. Although the angle at which the screen is mounted mayvary withinY wideY limits, the preferred angle which has obtainedsatisfactory results in actual practice is approxi'- mately 35 withrespect to the horizontal. A squeegee for forcing the ink through. thescreen is suitably mounted adjacent one side thereof and mechanism isprovided for withdrawing the squeegee from the screen during itsnon-printing stroke and for pressing the. squeegee against the screenduring the printing stroke thereof. An adjustment is provided for thesqueegee whereby the amount of ink. forced through the screen may beproperly controlled'.

Novel drive mechanism is mounted a-t one end of. the mainY supportingframe for properly driving and coordinating the various steps of theprinting process. As stated above, one. of the great objections anddisadvantagesv of earlier printing machines of this character has beenthe inability to. properly register the paper so as to obtain a nequality of work comparable to that of a lithographie process. The drivemechanism of the present invention is such as to permiteJ properregister of the paper against grippers which carry the paper around acylinder and against the screen, such grippers being gradually retardedin their rotary movement toward a sheet to be fed. thereto and beingstopped in their rotary movement momentarily at the time of gripping thepaper to enable the paper to thus 'be placed thereagainst and provide aproper register therefor.

The various advantages of the present invention and the specificmechanism which has been designed to attain the objects enumerated, willbecome evident upon a more detailed description of the machine. Tofacilitate an understanding of the construction and operationof themachine, the description thereof has been .divided into separateheadings as follows:

. The drive mechanism The screen reciprocating mechanism The inkingfountain The squeegee operating and adjusting mechanism . The sheetfeeding and delivery mechanism The operation of the machine The machinemay be embodied in. and. supportedV by a suitable main frame which, inthe illustrated. form of the invention, may include a pair of spacedsupporting frame members l located at the bottom of the machine and theupwardly extending supportingV members 2 and 3 at the front and: rearends of the machine respectively. The feed table 4 is located at thefront of the machine for the purpose of feeding sheets of paper to theprinting mechanism, and may be supported by spaced upwardly andangularly extending members 5 secured at the lower ends to thesupporting members I. Vertically extending spaced angle members .Vadjacent the rear of the machine are adapted to support a part of thedrive mechanism and may have additional angularly disposed supportingmembers 'I at the upper part of the machine to thereby provide a sturdyconstruction. Horizontally disposed spaced apart angle members 8 arelocated near the upper part of the machine to which various actuatingmeans may be mounted, and angularly disposed guide members 9 are'positioned at each side of. the frame to. support the screen frame forreciprocation.

The driving mechanism For the sake of clarity, the end of the machinewhere thev feeding of the paper takes place for the printing operationwill be referred to as the front' end of the machine, and the rear endthereof will be that end where the printed sheet is` delivered. Themotive power which actuates thedriving mechanism is preferably locatedat the rear end of the machine and comprises a suitableA support Hl onwhich. an electric motor ll may be mounted. The motor Il is providedwith a suitable shaft I2 to which is secured. a pulley I3 adapted todrive a pulley It mounted on the shaft I5 (see Fig. 2) by means such asthe belt` i6.

The shaft t5 is suitably mounted at each end thereof in the bearings Il'and I8, this latter bearing being mounted. on. the upwardly extendingsupporting member I9 which is in turn secured to the. transverselyextending angle member 2U forming a part of the main frame.

Any desirable means may be provided for connecting. the main drive shaftl5 to the driving mechanism so that the connection therebetween may bereleased to stop further operation of the machine. This may be done by asuitable clutch mechanism including a manually operated lever arm 2lsecured to a shaft 22 which has a small arm 23 also secured thereto sothat actuation. of the arm 2i will rotate the shaft and induce a rotarymotion of. the, arm 23. This. latter arm is provided with a link 24pivotally secured at its other end to an upwardly extending arm 25 bymeans of. the. pivot, pin 2B. The arm 25. is bifurcated at its upper endto provide a yoke 2l and is pivotally mounted to the supporting memberI3 i-n such a way that actuation of the` arm 2| will move the yoke 22'!vtoward the right or toward the leftas viewed in Fig. 2 for actuating theclutch mechanism.

The upper end of the arm 25 is suitably connected to a clutch mechanism28 tov thereby releasably connect the shaft l5 to the shaft 29. Thislatter shaft is connected to a speed reducer 3D of any' suitable andwell known construction whereby the shaft 3| thereof will rotate at areduced speed.

The shaft 3l has mounted thereon the large gear 32 adapted to be in meshwith a smaller gear 33 on the shaft 35:1 which also has secured theretothe small operating pinion 35 adapted to actuate thedrive mechanism forreciprocatingV the screen frame and properly coordinating the gripperfingers of the sheet delivery mechanism.

Figs. 13, 14 and 15 illustrate the preferred form of driving mechanismand the operation thereof will be made more clear by reference to thesefigures where the mechanism is shown apart from the other details of themachine as in Fig. 2. rlhe end of the shaft 34 is adapted to be mountedin a roller bearing 36 as shown in Fig.. 15. They drive mechanismincludes avertically reciprocating frame comprising the upper and lowerbars 3l' and t3. A rack frame 39 is adapted to be so mounted on thesebars 3'! and 33 so as to permit not only a vertical reciprocation of therack frame, but also a reciprocating movement from side to side on thesebars. The construction is such that the bars are stationary during sideto side reciprocation of the rack frame 39 thereon, but will be carriedwith the rack frame during vertical reciprocation thereof.

Upper and lower supporting bars 49 and 4| may be welded or otherwisesecured to the rack frame 39 and are adapted to support the bearings forthe rack frame to be mounted on the transverse bars 31 and 39. Themounting means of the upper bar 4D includes a pair of spaced members 42secured to one end thereof and adapted to support spaced apart rollerbearings 43 and 44, one on each edge of the bar 31. The other end of thesupporting bar 40 also has secured thereto a pair of similar members 45having roller bearings 45 and 41 located therebetween also in contactwith the upper and lower edges of the bar 41. The lower supporting bar4| is similarly constructed by being provided at one end thereof withthe supporting members 48 having the roller bearings 49 and 59 securedthereto and at its other end the members 5l with the roller bearings 52and 53 thereon.

The bar 31 at the upper part of the frame is adapted to be receivedbetweenthe upper rollers 43 and 46 and the lower rollers 44 and 41.Likewise, the lower bar 38 of the frame is received between the upperrollers 49 and 52 and the lower rollers 50 and 53. It will thus beevident from this construction that when the rack frame 39 is caused toreciprocate vertically, it will carry with it the upper and lower bars31 and 38. It will also be clear that the rollers mentioned aboveprovide a bearing surface to permit the rack '1 frame 39 to be movedfrom side to side on the bars 31 and 38.

The rack frame 39 has mounted at one side thereof a rack 54 which isadapted to be in mesh at all times with the pinion 35 mounted on theshaft 34. The rack 54 is composed of spaced vertically extending rackmembers 55 and 56 at 'each side thereof and with horizontally extendingrack portions 51 and 59 at the upper and lower ends thereofrespectively. The upper and lower rack portions join with the side rackportions 55 and 55 to thus provide a continuous rack of substantially arectangular shape with rounded corners which will be in mesh at alltimes with the pinion 35. Since the shaft 34 and pinion 35 mountedthereon are secured to a stationary part of the main frame, a rotationof the pinion 35 will cause a movement of the rack frame 39 in both ahorizontal and vertical direction. As the frame moves in a horizontalplane, it will remain stationary with respect to any vertical movement,and during the vertical reciprocation thereof no movement will occur ina horizontal plane except' during the period of movement when the pinion35 is in mesh with the rounded corners of the rack.

This movement of the rack frame 39 and the bars 31 and 39 on which it ismounted may be more easily understood by viewing Fig. 14. Here it willbe noted that the two horizontally eX- tending bars 31 and 38 areconnected at their ends by means of a vertically extending flange 59 ateach end thereof. Each flange 59 is provided with a roller 59 extendingin one direction and other rollers 5l positioned at right anglesthereto. A guide bar 52 extends vertically adjacent each of the ila-nges59 and has a centrally located elongated groove therein adapted toreceive the rollers 6I. The rollers 65 are adapted to bear against thatportion of each guide 62 located adjacent the central groove therein.

The manner in which the drive mechanism just described actuates thevarious parts of the ma"- chine to coordinate the various steps of theprintf"- ing operation will become more apparent upon a descriptionofeach of the mechanisms separately. For the present it Will be suicientto understand that operation of the motor l I, when the clutch 29 isengaged, will rotate the shaft 34 and the pinion 35 in mesh with theteeth on the rack 54. In the position of the rack shown in Figs. 2 and13, if the pinion 35 is rotating in a clockwise direction, the rack andits frame 39 will be moving toward the left and the horizontal bars 31and 38 Will remain stationary until the rounded corners of the rack arereached at which time the entire frame will begin to move upwardly. Thisupward movement continues until the bottom of the rack portion 55 isreached at which time the frame and its connected parts will reach itsuppermost position. There will then be a dwell or pause in the verticalmovement of the frame while it is moving back toward the right and untilthe pinion 35 reaches the rack portion 55, at which time the frame willbe moved downwardly. This action occurs during operation of the machinecontinuously and will act to reciprocate the screen frame, will properlyapply the ink to the screen and will actuate the grippers at the propermoment while they remain stationary during the above referred to dwell.During this dwell, the grippers will be opened by mechanism to bedescribed hereinafter at which time the paper may be moved thereagainstin proper register and then moved against the screen for the printingstep.

The screen reciprocating mechanism In describing the screen and itsconnection with the rack frame 39 whereby the screen is caused toreciprocate on the main frame, reference will be particularly made toFigs. l, 3, 4, 5, 6, '1 and 8. A rack 63 is positioned vertically ateach side of the moving frame and is secured as by welding or othersuitable means to the upper and lower horizontally extending cross bars31 and 38. Thus, as the bars 31 and 38 are reciprocated in a verticalplane by movement of the rack frame 39, the vertically extending racks93 will also be caused to reciprocate vertically. A gear 54 is mountedat each side of the main frame and is adapted to rotate freely on theshaft 55. These gears 64 have a rotary reciprocating motion which istransmitted thereto by being in mesh with the racks 53. As these racksreciprocate vertically,

va rotary reciprocation of the gears 64 Will oca reciprocation of thescreen and screen frarne in an angular direction, as more clearly seenin Figs. 4, 5 and 6. A counter-balancing spring 59 is suitably securedto each of the gears `54 at one end thereof and to a stationary part ofthe main frame at the other end thereof to aid in the operation of thevarious reciprocating parts whereby less power is necessary to operatethe machine.

The novel construction of the screen frame whereby the screen may beadjustably mounted therein may be more clearly understood by referenceto Figs. 1'7 through 21 inclusive. Here it will be seen that the screenframe at each side thereof is provided with a side member l@ to whichthe upper rack 68 is secured along one edge thereof and a lower rack 'ilis secured adjacent the bottom edge thereof. The screen frame is adaptedlto ride in guide members consisting of spaced guide bars 'I2 and 'I3secured to the inner side of the angularly extending side frame members9. The two guide bars 'l2 and 'I3 being mounted in spaced relation willthus provide an elongated groove lll. The frame itself has a pair ofrollers l5 mounted on the underside of the rack 68 and a second pair ofrollers 'i6 suitably mounted adjacent the lower rack which extend withinthe space 'ifi to provide support for the screen frame duringreciprocation thereof. The rollers l5 at each side of the screen frameare adapted to ride on the guide bars '|2, maintaining perfect sidewisealignment, and the rollers 'I'G are mounted at substantially rightangles with respect thereto and ride on the guide bars 13.

The screen itself is mounted on an angle iron frame 'il on which may bemounted iloating wooden frame members extending along the four sides ofthe screen. The lower angle member 'I8 is adapted to rest on a secondangle member la which has secured thereto a pair of clamping members 80.Each clamping member is provided with a screw threaded clamp 8| so thatas the screen frame is inserted at the lower end thereof between theangle member 'I9 and the clamping members 89, the members 8| may beutilized to clamp the screen in place.

A novel feature of this machine is the provision of a iine adjustmentfor the screen within the screen frame whereby the position of thescreen therein may be adjusted for purposes of proper registry. When thescreen is thus adjusted, it will permit a sheet of paper to be fed intothe machine at the same point each time. It never becomes necessary tochange the position of any gauge pins or other registering devicesagainst which the edge of a sheet of paper being fed into the machine isto be placed. The adjustable feature of the screen and its frame is moreclearly illustrated in Figs. 17, and 21 where it will be noted that theupper horizontal edge of the screen frame is provided with an innerangle member 82 and an outer angle member 83. rlhese angle members areso positioned relative to each other that one leg of each member is incontact with each other and the other legs thereof extend upwardly insubstantial parallelism. rlhe upwardly extending leg of the angle member83 is provided with a T-slot 84 adapted to receive the threaded end ofan adjusting nut 85. The threaded end thereof is received by a threadedopening in a block 86 secured to the angle member 82. The

other leg of the angle member 83 has a slot 8l therein adapted toreceive a clamping nut 88l which extends through the opening 8l and issecured to the angle member 82. Thus it will be evident that by screwingthe adjusting member 85 in one direction or the other, a correspondingmove- -ment of the angle bar 82 will be effected. As may screen is inproper registry, the clamps 8| and 88 may be tightened and the screenwill be ready for the printing operation.

When the rack frame 39 is caused to recprocate vertically carrying withit the racks B3, the two gears 64 in mesh therewith will have a rotaryreciprocating movement. Likewise, the screen and screen frame withinwhich it is mounted, having suitable racks 68 also in mesh with thegears 64, will be caused to reciprocate in an angular direction throughthe guide bars 'l2 and 13. A novel inking fountain and means fordistributing the ink over the screen in preparation for the printingoperation is located at the lower end of the screen frame and will nowbe described.

The inking fountain The lower end of the screen frame is provided with aforwardly and upwardly extending ink retaining member 89 as may be seenin Figs. 4, '7 and 8, whereby a fountain is provided extending the widthof the screen at the lower end thereof within which a quantity of ink 90may be provided at all times and may be moving with the screen duringthe reciprocation thereof.

The ink is caused to be distributed over a portion of the screen at thelower side thereof by means of a movable framework consisting of anupper transversely extending rod 9| having a roller 92 at each sidethereof adapted to be rolled against the upper guide bars l2 as thescreen moves upwardly. A lower transversely extending rod 93 isconnected with the rod 9| by means of the connecting bars Sil at eachend thereof. Each of the racks 68 has an extension 95 at the upper endthereof adapted to have secured thereto a carrying member 96 which maytake any suitable form and, in the illustrated embodiment of theinvention, may comprise merely a block of metal. A stop member 91 isadapted to be welded or otherwise suitably secured to the side framemembers 8 and 9 at the juncture thereof and against which the rollers 92will bear to support the rods 9| and 93 after the screen frame has moveddownwardly a suflicient distance.

ln the operation of the ink distributor, when the screen frame movesupwardly, the lower rod 93 will be immersed in the ink 90 as shown inFig. 4. The frame consisting of the rods 9| and 93 will be carriedupwardly by the carrier members 96 for the full distance of the screenmovement, but on the downward movement thereof, the rollers 92 will comeagainst the stop members 9? and withdraw the lower rod 93 from the ink98 as the screen continues to move downwardly, at which time therelative position of these parts will be like that shown in Fig. '7. Asthe rod is withdrawn from the ink, it will carry with it a quantity ofthe ink and distribute it over the lower part of the frame. On the nextupward movement of the screen, the ink thus distributed will be carriedwith the screen, but as it moves downwardly again the ink will be pickedup by the squeegee and forced through the open interstices of the screenand transferred to a sheet of paper on the opposite side thereof forprinting. The printing operation and the construction of the squeegeewill now be described.

The squeeyee operating and adjusting mechanism Reference will now bemade more particularly to Figs. 3, 4, 5, 6 and 9 where the flexiblesqueegee is indicated by the numeral 98. The squeegee is suitablymounted on a bar 99 extending transversely of the screen and screenframe and may be of any suitable length. That is to say, if the printingimpression is to take place throughout the entire width of the screen,then the squeegee and its mounting bar 9d may extend the full widththereof. On the other hand, if the subject matter to be printed is toconsume a relatively small or narrow area on the screen, then thesqueegee and its supporting bar may be of a width just sufficient tocover the printing area. This type of construction is also advantageousfor simultaneous multi-color printing whereby the inking fountain may beprovided with partitions with a different colored ink in each sectionthereof and a plurality of squeegees may be mounted so that each willprint with a different colored ink.

One or more of the squeegee bars 99 may be clamped in place on amounting member which extends throughout the width of the screen. Anysuitable clamping or mounting means can be utilized for securing thesqueegee in place, and the illustrated form includes a clamping memberIOI having a block |02 adapted to be placed against the bar or mountingmeans |00 and a second smaller block |03 adapted to bear against thesqueegee bar 99. Suitable bolts may then be inserted through the memberIDI and the blocks |02 and |03 to thereby clamp the squeegee bar 09 inplace. This construction is clearly illustrated in Figs. 4, and 6.

It is necessary that the squeegee 98 be held forcibly against the screenduring the printing operation to transfer the ink therethrough to thepaper on the opposite side thereof. It is equally necessary that thesqueegee be removed from the screen during the non-printingreciprocating movement thereof. To accomplish this result I haveprovided novel mechanism for pressing the squeegee against the screenduring the downward movement thereof and for elevating the squeegee awayfrom the screen during the upward movement thereof. This mechanismcomprises a plate |04 at each side of the screen frame to which thesupporting member |00 is secured. Each plate |04 is mounted on anextension |05 of a bar |00 which extends downwardly at each side of themachine and is mounted for a rotary. movement on the transverselyextending shaft |01 suitably mounted in bearings |08. The bearf ings |08are located on a transversely extending stationary angle member |00 ofthe main frame to which the counter-balancing spring 09 may also besecured as shown. The upper ends of the extensions |05 are securedtogether by means of the transversely extending bar H0.

An adjusting bar I|| is also located at each side of the machine and ismounted for pivotal movement on the bars |00 by suitable pivot pins II2.The upper end of each adjusting bar I II is bifurcated as indicated at|I3 and is adapted to be received within the sides of a U-shaped bracketII4 mounted on the connecting bar I|0. An adjusting screw I I5threadedly engages each of the brackets I|4 whereby it may extendbetween the sides thereof, each screw I I5 being provided with anannular groove IIB adjacent its inner end to receive the bifurcated end||3 of the bar III. This construction admits of a suitable adjustment tobe made with respect to the pressure of the squeegee 98 against thescreen during the printing operation. This adjustment may becomenecessary because of different circumstances such, yfor example, aswhere the viscosity of the ink may vary thus requiring more or lesspressure to force it through the interstices of the screen.

The actuating means for raising and lowering the squeegee is secureddirectly to each of the adjusting bars III and moves the squeegee thesame distance upon each operation thereof. Thus the force with which thesqueegee bears against the screen will depend upon the initial locationof the adjusting bars |I| with respect thereto. If the adjusting screwsII5 are moved outwardljr from the brackets H4, the bars III will beelevated so that when the actuating mechanism moves the squeegee againstthe screen, it will bear against it with a lesser force. Likewise, if agreater force is desired, then the adjusting screws II5 may be movedinwardly whereby the adjusting bars I I I will be closer to the screen.

Additional clamping means in the form of a member I at each side of themachine and secured to the cross bar I I is provided which has anelongated clamping bolt ||8 threadedly secured thereto. The outer end ofthis bolt is adapted to bear against the clamping means |0I for thesqueegee supporting bar whereby the entire structure is securely held inplace.

The actuating means for moving the squeegee toward and away from theprinting screen con--l sists of a slide member |I9 at each side of themachine having an elongated recess |20 therein adapted to receive theshaft 65. One end of the slide II9 is secured to the adjusting bar IIIas at |2| whereby a reciprocating movement of the slide member II9 willcarry with it the bar III and the squeegee connected thereto through themeans described above. The sliding movement of the slide member takesplace about the shaft 65.

A shaft or rod |22 extends transversely of the machine and is secured ateach end thereof to a slide member II9. Two other transversely extendingrods |23 and |24 are also mounted on the slide members II9 at theopposite end thereof. The rod |22 has a cam follower |25 rotatablymounted at each end thereof and similar cam followers |20 are located ateach end of the rod |23.

while the cam followers |21 are mounted at each end of the rod |24. Anactuating cam |28 is secured to the shaft 05 at each end thereof by anysuitable means such as the clamping member |29 whereby the cam will berotated continuously in the same direction with the shaft 65. The meansby which this shaft rotates will be explained hereinafter.

Between the ends of the shaft and the various rods above mentioned, alimiting bracket is located which is provided with spaced side members|30 adapted to embrace the shaft 65 and which has at one end thereof aspacer member |3I and at its other end a slotted bracket |32. The rod|22 is adapted to be received by the slot in the member |32 and limitsthe reciprocating movement of the slide member I I9.

The shaft 65 is mounted in suitable bearings |33 and |34 secured to thesupporting side frame members 8 of the main frame. One end of the shaft65 has a bevel gear |35 secured thereto and is adapted to be in meshwith another bevel gear |30 mounted on the shaft |37 which extends alongone sideof the machine from the front to the rear thereof. At the rearend of the machine, the shaft |31 is mounted for rotation in a bearing|38 and has a toothed wheel |39 secured thereto adjacent the rear end. Achain drive |40 is in engagement with the toothed Wheel |39 and alsoengages a small toothed wheel |4| on the y; shaft 3|. The chain thenpasses over an idler 1 I wheel |42 and as the shaft 3| is the drivingshaft emanating from the speed reducer, it Will thus' drive the shaft|31 by means of the chain |49. Obviously, rotation of the shaft |31 andthe bevel gear |36 thereon in mesh with the bevel gear |35 will rotatethe shaft 65 to which is secured the cams |28. In the position of thecam |28 as shown in Fig. 4, the edge thereof Vis bearing downwardlyagainst the rollers of the slide member I9. When this occurs, the slidemember and the parts connected thereto, including the adjusting bars thebars ||J6 and the squeegee 9B will also be moved downwardly so that thesqueegee will exert a pressure against the printing screen. This drivingmeans is so synchronized with respect to the reciprocating movement ofthe screen and screen frame as to actuate the squeegee 98 toward andagainst the screen as the screen moves downwardly. When the screenreaches its lowermost position, or before such time if so desired, thecam |28 will be rotated to its position shown in Fig. 5 where the edgethereof bears against the rollers i2? and elevates the slide members ||9together with the Squeegee connected thereto. As the cam continues torotate, the edge thereof will also contact the rollers |26 to maintainthe squeegee in its elevated position during the upward movement of thescreen.

` As explained above, during the upward stroke of the screen, the lowercross member 93 of the inking frame will be immersed in the ink 90, sothat as the screen moves downwardly to its lowermost position, theinking frame will distribute a quantity of ink across the bottom portionof the screen. The ink will thus remain in this position until thescreen again reaches its uppermost position, at which time the cam |28is operated to press the squeegee against the screen and the ink whichhas been distributed thereon, so that such ink will be forced throughthe screen and onto a sheet of paper at the opposite side thereof forthe printing operation as the screen moves downwardly.

The sheet feeding and delivery mechanism The sheet of paper to beprinted may either be fed by hand to the machine or any suitable form ofautomatic sheet feeding means may be used. In the illustrated form ofthe invention, no automatic sheet feeding. means have been disclosed,but the manner in which the sheet is gripped and rolled against thescreen for printing will be the sameeven though the sheets are fed byhand. The sheets may be manually placed on the feeding table 4 and fedto a drum |44 located beneath the screen and which has a gear at eachside thereof mountedv for rotation on the transversely extending shaft|46. These various parts may be more clearly understood by viewing Figs.3, 4, 5, 10, 12 and 16.

These gears |45 are adapted to be in mesh with the racks on theunderside of the screen frame so that as the screen reciprocates, thedrum will also have a rotary reciprocating movement. The drum isprovided with an lopening |41 extending substantially throughout thelength thereof against one edge of which suitable gripper fingers may beactuated to grasp the edge of a sheet of paper being fed thereto androll it against the screen. A number of strengthening webs or spacers|48 may also be disposed in spaced relation throughout the length of thedrum if so desired.

. The gripper finger assembly comprises a supporting bar |49 extendingsubstantially the length of the drum and mounted along one edge of theopening |47. A plurality of gripper fingers |55 are adapted to bereciprocated in such a way that when they are in closed position, theywill bear against an edge of the supporting bar |49 and when in openposition they will be adapted to receive the edge of a sheet of paper.Each gripper |50 has an inwardly extending tail piece |5| slidablymounted within a blocl; on the supporting bar |49. The tail piece |5|has a projection |53 thereon against which a rotary recipro- :atingactuator |54 is adapted to bear for actuating the gripper linger |5 andmoving it to its open position to receive a sheet of paper. The actuator|54 is suitably secured on the rock shaft |55 whereupon a rocking of theshaft in one direction will urge the gripper outwardly away from thedrum and a movement in the opposite direction will permit the coiledtension spring |56 secured thereto to draw the gripper inwardly byreason of the connection of the other end of the spring toa rod |57extending lengthwise of the drum. Any suitable number of gripperassemblies may be located in spaced relation on the supporting bar |49and along the shaft I 55 so that a sufficient number may grasp the edgeof a sheet and roll the sheet against the underside of the screen in itsdownwardly movement.

Suitable mechanism is provided for rocking the shaft |55 each time thedrum |44 reaches the end of its rotary reciprocating movement in bothdirections. Fig. 4 shows one of the grippers in its closed position forgripping the edge of a sheet of paper for printing and Fig. 12 shows thegripper in its open position with the shaft |55 rotated a suflcientamount for the actuating member |54 to move the gripper |59 outwardly.It is just as necessary to open the grippers at or before the end oftheir rotary reciprocating movement in the opposite direction so thatthe printed sheet may be delivered from the machine. The actuatingmechanism for rocking the shaft |55 may be more clearly understood byreference to Figs. 10 and 11 where it will be noted that the rock shaft|55 is mounted for rotation with the drum |44 and extends beyond thedrum whereby a cross member |58 may be keyed thereto. This cross member|58 rotatably supports the cam followers |59 and |59 at each endthereof. A suitably mounted cam |61 is so located that when the rotationof the drum is in a counterclockwise direction and the grippers thereofare in the position shown in Figs. 4 and 12, the cam |6| will be in aposition relative to the cam roller |59 as shown in Fig. l1. At thismoment, suitable mechanism to be described hereinafter, will elevate thecam |6| against the cam follower |59 which will thus impart a rockingmovement of the shaft |55 in a clockwise direction. By reference toFigs. 4 and 12, it will be obvious that such a rocking of the shaft |55will cause the gripper fingers |50 tobe moved to open position inreadiness for receiving the edge of a sheet of paper. l

A second cam |62 is mounted on an vupwardly extending support |63secured to the horizontal stationary support |64 at the opposite side ofthe drum |44, whereby, when the drum is vrotated in a clockwisedirection, the cam roller will come against the undercurved side of thecam |62 and again rotate the rock shaft |55 in a clockwise direction toopen the gripper fingers |50 'and permit the printed sheet being heidthereby to lbe delivered from the machine.

The shaft las supporting the drum V44 is' suit- 13 ably mounted inybearings |55 also located on and secured to the horizontally extendingstationary frame member |84.

When paper is fed to the machine along the table 4, it is necessary thatadjustable side guide members be provided to compensate for differentvwidths of paper even though the machine has been designed to permit afeeding of the paper to the same point at all times. One form which theside guide or stop member may take is illustrated in Fig. 3 where thestop member |58 is shown as being secured to a slidably mounted bar I9?mounted for a sliding movement within the guide members |63 and |59. Theouter end of the bar may be provided with a plurality of spaced apartopenings |10 adapted to receive a pin |1'I extending between the sidesof the guide |89. in this way, the pin |1| may be removed and the bar|91 together with the stop member |59 thereon may be moved in eitherdirection to a location suitable for the size of the sheet of paperbeing fed, and the pin then replaced in a suitable opening |19 whichwill hold the side stop in its proper position. It will be evident thatany other suitable form of side stop as well as securing or clampingmeans therefor may be used if so desired.

As the paper is being fed to the grippers |50 it is desirable that aplurality of guide fingers be provided for guiding the edge of the sheetdownwardly and to prevent the edge from curling upwardly. To this end atransversely extending supporting bar |12 spaced upwardly from the table4 is provided which has a plurality of guide fingers |19 curveddownwardly and extending toward the drum. The fingers |13 terminateshort of the position of the gripper lingers |50 in sheet receivingposition so that no interference with the operation of the grippers willresult.

A plurality of movable gauge or register pins are also provided toenable the operator of the machine to initially position the paperproperly for feeding to the grippers. As the operator feeds the sheettoward the drum, the forward edge thereof will iirst come against aplurality of these pins for a preliminary positioning of the sheet. Whenthe gripper fingers open and are in readiness to receive the sheet, thenthe pins move upwardly. The cylinder gripper fingers then slightly bumpagainst the sheet assuring registration on the cylinder itself. To theattainment of this end, a transversely extending pin supporting bar |14.is provided having a plurality of spaced apart gauge pins extendingdownwardly therefrom and positioned closely adjacent the drum |44. Eachend of the bar |14 is rounded so that it may be rotatably mounted withina supporting member |15 located at each side of the machine. The bar |14is caused to rock by means of an extension |11 secured to one endthereof, which extension is adapted to be received between the legs of aU-shaped bracket |18 (see Fig. 10). Suitable securing means are providedto fasten the end of the member |11 within this bracket and, as will bepresently pointed out, a vertical reciprocation of the bracket |18 willcarry the end of the member |11 with it and thus cause a rockingmovement of the bar |14 to raise and lower the gauge pins |15.

The bracket |18 is secured to one of a pair of spaced supporting plates|19 which, in turn, are each secured at their inner ends to a verticallyreciprocating bar |80. This bar |80 is guided in its vertical movementby the bracket |8| and has at its upper end a transverse extension |82adapted to receive an adjusting screw |83. The

14 screw |83 may be adjusted upwardly or downwardly to adjust thedownward movement of the bar 180 and its connected parts since it bearsagainst the upper end of the bracket |8| in its lowermost position.

Referring again to Fig. 1l, it will be clear that the lower end of thereciprocating bar is pivotally connected to a link |84 having a slot |85in its outer end adapted to receive a suitable pin |86 for purposes ofguiding the movement of the link. The cam l6| above referred to asactuating the rock shaft |55, is mounted on the link |84 and is movabletherewith. It will thus be clear that an upward movement of thereciprocating bar |80 will perform two functions, one of which is tocarry with it the bracket |11 for rocking the bar |14 in a clockwisedirection for operating the gauge pins |15, and the other of which is toelevate the cam |6| to rock the shaft |55 also in a clockwise directionto open the gripper ngers |50.

The actuating mechanism for reciprocating the bar |80 and its connectedparts consists of a pair of spaced apart plates |81 secured to theplates |19 and which are adapted to support between their outer ends acam follower |88. A cam |89 of a suitable configuration is keyed to theshaft |31 which is journaled in its forward end by a bearing |90 securedto the upwardly extending supporting member |9| of the angle member |64.As the cam |89 rotates, it will contact the cam roller |88 and elevatethe parts connected therewith which include the reciprocating bar |80and the rock shaft |55 as well as the rocker bar |14.

When the lower part of the cam |89 is reached, the various parts willdrop downwardly by gravity which will actuate the gauge pins |15 and thegripper fingers |50 in the opposite direction. The drive means forrotating the shaft |31 have been described above and the cam |89 is sopositioned thereon as to actuate these various parts in timed relationso as to grasp the sheet and roll it against the underside of the screenin properly timed relation with the reciprocation thereof.

A delivery mechanism for delivering the printed sheet from the machineis also provided. It will be understood that any suitable form ofmechanism may be utilized for this purpose, the means disclosed hereinbeing merely for purposes of illustration. The delivery means disclosedmay be more readily understood by reference to Figs. l2 and 16 where agripper device generally indicated at |92 is mounted on a chain drivingmeans |93 located at each side of the machine and immediately below thedrum |44. The chain |93 is driven by means of a toothed wheel |94mounted at each end of a transversely extending shaft |95 at the forwardend of the machine and another toothed wheel |96 at each side of themachine located rearwardly thereof. The shaft |95 is mounted forrotation in suitable bearings |91 1ocated at the forward end of the mainsupporting frame and the toothed wheels |96 are mounted for rotation ona transversely extending shaft |98 which has a bevel gear |99 mounted atone end thereof.

The chains |93 and the gripper devices |92 are caused to movecontinuously in a counter-clockwise direction as indicated in Fig. l2 bymeans of a bevel gear 200 in mesh with the bevel gear |99, which gear200 is mounted on a rearwardly extending shaft 20| `iournaled inbearings 202 and 203 mounted at the front and rear ends of the framerespectively.

Referring momentarily .to Fig. 2 it will be ap-

